/*

 * jmorecfg.h

 *

 * Copyright (C) 1991-1995, Thomas G. Lane.

 * This file is part of the Independent JPEG Group's software.

 * For conditions of distribution and use, see the accompanying README file.

 *

 * This file contains additional configuration options that customize the

 * JPEG software for special applications or support machine-dependent

 * optimizations.  Most users will not need to touch this file.

 */





/*

 * Define BITS_IN_JSAMPLE as either

 *   8   for 8-bit sample values (the usual setting)

 *   12  for 12-bit sample values

 * Only 8 and 12 are legal data precisions for lossy JPEG according to the

 * JPEG standard, and the IJG code does not support anything else!

 * We do not support run-time selection of data precision, sorry.

 */



#define BITS_IN_JSAMPLE  8	/* use 8 or 12 */





/*

 * Maximum number of components (color channels) allowed in JPEG image.

 * To meet the letter of the JPEG spec, set this to 255.  However, darn

 * few applications need more than 4 channels (maybe 5 for CMYK + alpha

 * mask).  We recommend 10 as a reasonable compromise; use 4 if you are

 * really short on memory.  (Each allowed component costs a hundred or so

 * bytes of storage, whether actually used in an image or not.)

 */



#define MAX_COMPONENTS  10	/* maximum number of image components */





/*

 * Basic data types.

 * You may need to change these if you have a machine with unusual data

 * type sizes; for example, "char" not 8 bits, "short" not 16 bits,

 * or "long" not 32 bits.  We don't care whether "int" is 16 or 32 bits,

 * but it had better be at least 16.

 */



/* Representation of a single sample (pixel element value).

 * We frequently allocate large arrays of these, so it's important to keep

 * them small.  But if you have memory to burn and access to char or short

 * arrays is very slow on your hardware, you might want to change these.

 */



#if BITS_IN_JSAMPLE == 8

/* JSAMPLE should be the smallest type that will hold the values 0..255.

 * You can use a signed char by having GETJSAMPLE mask it with 0xFF.

 */



#ifdef HAVE_UNSIGNED_CHAR



typedef unsigned char JSAMPLE;

#define GETJSAMPLE(value)  ((int) (value))



#else /* not HAVE_UNSIGNED_CHAR */



typedef char JSAMPLE;

#ifdef CHAR_IS_UNSIGNED

#define GETJSAMPLE(value)  ((int) (value))

#else

#define GETJSAMPLE(value)  ((int) (value) & 0xFF)

#endif /* CHAR_IS_UNSIGNED */



#endif /* HAVE_UNSIGNED_CHAR */



#define MAXJSAMPLE	255

#define CENTERJSAMPLE	128



#endif /* BITS_IN_JSAMPLE == 8 */





#if BITS_IN_JSAMPLE == 12

/* JSAMPLE should be the smallest type that will hold the values 0..4095.

 * On nearly all machines "short" will do nicely.

 */



typedef short JSAMPLE;

#define GETJSAMPLE(value)  ((int) (value))



#define MAXJSAMPLE	4095

#define CENTERJSAMPLE	2048



#endif /* BITS_IN_JSAMPLE == 12 */





/* Representation of a DCT frequency coefficient.

 * This should be a signed value of at least 16 bits; "short" is usually OK.

 * Again, we allocate large arrays of these, but you can change to int

 * if you have memory to burn and "short" is really slow.

 */



typedef short JCOEF;





/* Compressed datastreams are represented as arrays of JOCTET.

 * These must be EXACTLY 8 bits wide, at least once they are written to

 * external storage.  Note that when using the stdio data source/destination

 * managers, this is also the data type passed to fread/fwrite.

 */



#ifdef HAVE_UNSIGNED_CHAR



typedef unsigned char JOCTET;

#define GETJOCTET(value)  (value)



#else /* not HAVE_UNSIGNED_CHAR */



typedef char JOCTET;

#ifdef CHAR_IS_UNSIGNED

#define GETJOCTET(value)  (value)

#else

#define GETJOCTET(value)  ((value) & 0xFF)

#endif /* CHAR_IS_UNSIGNED */



#endif /* HAVE_UNSIGNED_CHAR */





/* These typedefs are used for various table entries and so forth.

 * They must be at least as wide as specified; but making them too big

 * won't cost a huge amount of memory, so we don't provide special

 * extraction code like we did for JSAMPLE.  (In other words, these

 * typedefs live at a different point on the speed/space tradeoff curve.)

 */



/* UINT8 must hold at least the values 0..255. */



#ifdef HAVE_UNSIGNED_CHAR

typedef unsigned char UINT8;

#else /* not HAVE_UNSIGNED_CHAR */

#ifdef CHAR_IS_UNSIGNED

typedef char UINT8;

#else /* not CHAR_IS_UNSIGNED */

typedef short UINT8;

#endif /* CHAR_IS_UNSIGNED */

#endif /* HAVE_UNSIGNED_CHAR */



/* UINT16 must hold at least the values 0..65535. */



#ifdef HAVE_UNSIGNED_SHORT

typedef unsigned short UINT16;

#else /* not HAVE_UNSIGNED_SHORT */

typedef unsigned int UINT16;

#endif /* HAVE_UNSIGNED_SHORT */



/* INT16 must hold at least the values -32768..32767. */



#ifndef XMD_H			/* X11/xmd.h correctly defines INT16 */

typedef short INT16;

#endif



/* INT32 must hold at least signed 32-bit values. */



#ifndef XMD_H			/* X11/xmd.h correctly defines INT32 */

typedef long INT32;

#endif



/* Datatype used for image dimensions.  The JPEG standard only supports

 * images up to 64K*64K due to 16-bit fields in SOF markers.  Therefore

 * "unsigned int" is sufficient on all machines.  However, if you need to

 * handle larger images and you don't mind deviating from the spec, you

 * can change this datatype.

 */



typedef unsigned int JDIMENSION;



#define JPEG_MAX_DIMENSION  65500L  /* a tad under 64K to prevent overflows */





/* These defines are used in all function definitions and extern declarations.

 * You could modify them if you need to change function linkage conventions.

 * Another application is to make all functions global for use with debuggers

 * or code profilers that require it.

 */



#define METHODDEF static	/* a function called through method pointers */

#define LOCAL	  static	/* a function used only in its module */

#define GLOBAL			/* a function referenced thru EXTERNs */

#define EXTERN	  extern	/* a reference to a GLOBAL function */





/* Here is the pseudo-keyword for declaring pointers that must be "far"

 * on 80x86 machines.  Most of the specialized coding for 80x86 is handled

 * by just saying "FAR *" where such a pointer is needed.  In a few places

 * explicit coding is needed; see uses of the NEED_FAR_POINTERS symbol.

 */



#ifdef NEED_FAR_POINTERS

#define FAR  far

#else

#define FAR

#endif





/*

 * On a few systems, type boolean and/or its values FALSE, TRUE may appear

 * in standard header files.  Or you may have conflicts with application-

 * specific header files that you want to include together with these files.

 * Defining HAVE_BOOLEAN before including jpeglib.h should make it work.

 */



#ifndef HAVE_BOOLEAN

typedef int boolean;

#endif

#ifndef FALSE			/* in case these macros already exist */

#define FALSE	0		/* values of boolean */

#endif

#ifndef TRUE

#define TRUE	1

#endif





/*

 * The remaining options affect code selection within the JPEG library,

 * but they don't need to be visible to most applications using the library.

 * To minimize application namespace pollution, the symbols won't be

 * defined unless JPEG_INTERNALS or JPEG_INTERNAL_OPTIONS has been defined.

 */



#ifdef JPEG_INTERNALS

#define JPEG_INTERNAL_OPTIONS

#endif



#ifdef JPEG_INTERNAL_OPTIONS





/*

 * These defines indicate whether to include various optional functions.

 * Undefining some of these symbols will produce a smaller but less capable

 * library.  Note that you can leave certain source files out of the

 * compilation/linking process if you've #undef'd the corresponding symbols.

 * (You may HAVE to do that if your compiler doesn't like null source files.)

 */



/* Arithmetic coding is unsupported for legal reasons.  Complaints to IBM. */



/* Capability options common to encoder and decoder: */



#define DCT_ISLOW_SUPPORTED	/* slow but accurate integer algorithm */

#define DCT_IFAST_SUPPORTED	/* faster, less accurate integer method */

#define DCT_FLOAT_SUPPORTED	/* floating-point: accurate, fast on fast HW */



/* Encoder capability options: */



#undef  C_ARITH_CODING_SUPPORTED    /* Arithmetic coding back end? */

#define C_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */

#define C_PROGRESSIVE_SUPPORTED	    /* Progressive JPEG? (Requires MULTISCAN)*/

#define ENTROPY_OPT_SUPPORTED	    /* Optimization of entropy coding parms? */

/* Note: if you selected 12-bit data precision, it is dangerous to turn off

 * ENTROPY_OPT_SUPPORTED.  The standard Huffman tables are only good for 8-bit

 * precision, so jchuff.c normally uses entropy optimization to compute

 * usable tables for higher precision.  If you don't want to do optimization,

 * you'll have to supply different default Huffman tables.

 * The exact same statements apply for progressive JPEG: the default tables

 * don't work for progressive mode.  (This may get fixed, however.)

 */

#define INPUT_SMOOTHING_SUPPORTED   /* Input image smoothing option? */



/* Decoder capability options: */



#undef  D_ARITH_CODING_SUPPORTED    /* Arithmetic coding back end? */

#define D_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */

#define D_PROGRESSIVE_SUPPORTED	    /* Progressive JPEG? (Requires MULTISCAN)*/

#define BLOCK_SMOOTHING_SUPPORTED   /* Block smoothing? (Progressive only) */

#define IDCT_SCALING_SUPPORTED	    /* Output rescaling via IDCT? */

#undef  UPSAMPLE_SCALING_SUPPORTED  /* Output rescaling at upsample stage? */

#define UPSAMPLE_MERGING_SUPPORTED  /* Fast path for sloppy upsampling? */

#define QUANT_1PASS_SUPPORTED	    /* 1-pass color quantization? */

#define QUANT_2PASS_SUPPORTED	    /* 2-pass color quantization? */



/* more capability options later, no doubt */





/*

 * Ordering of RGB data in scanlines passed to or from the application.

 * If your application wants to deal with data in the order B,G,R, just

 * change these macros.  You can also deal with formats such as R,G,B,X

 * (one extra byte per pixel) by changing RGB_PIXELSIZE.  Note that changing

 * the offsets will also change the order in which colormap data is organized.

 * RESTRICTIONS:

 * 1. The sample applications cjpeg,djpeg do NOT support modified RGB formats.

 * 2. These macros only affect RGB<=>YCbCr color conversion, so they are not

 *    useful if you are using JPEG color spaces other than YCbCr or grayscale.

 * 3. The color quantizer modules will not behave desirably if RGB_PIXELSIZE

 *    is not 3 (they don't understand about dummy color components!).  So you

 *    can't use color quantization if you change that value.

 */



#define RGB_RED		0	/* Offset of Red in an RGB scanline element */

#define RGB_GREEN	1	/* Offset of Green */

#define RGB_BLUE	2	/* Offset of Blue */

#define RGB_PIXELSIZE	3	/* JSAMPLEs per RGB scanline element */





/* Definitions for speed-related optimizations. */





/* If your compiler supports inline functions, define INLINE

 * as the inline keyword; otherwise define it as empty.

 */



#ifndef INLINE

#ifdef __GNUC__			/* for instance, GNU C knows about inline */

#define INLINE __inline__

#endif

#ifndef INLINE

#define INLINE			/* default is to define it as empty */

#endif

#endif





/* On some machines (notably 68000 series) "int" is 32 bits, but multiplying

 * two 16-bit shorts is faster than multiplying two ints.  Define MULTIPLIER

 * as short on such a machine.  MULTIPLIER must be at least 16 bits wide.

 */



#ifndef MULTIPLIER

#define MULTIPLIER  int		/* type for fastest integer multiply */

#endif





/* FAST_FLOAT should be either float or double, whichever is done faster

 * by your compiler.  (Note that this type is only used in the floating point

 * DCT routines, so it only matters if you've defined DCT_FLOAT_SUPPORTED.)

 * Typically, float is faster in ANSI C compilers, while double is faster in

 * pre-ANSI compilers (because they insist on converting to double anyway).

 * The code below therefore chooses float if we have ANSI-style prototypes.

 */



#ifndef FAST_FLOAT

#ifdef HAVE_PROTOTYPES

#define FAST_FLOAT  float

#else

#define FAST_FLOAT  double

#endif

#endif



#endif /* JPEG_INTERNAL_OPTIONS */

